What is the Rarest of Twins? Semi-Identical Twins
Twins come in all shapes and sizes, but the rarest of them all are semi-identical twins. According to a report released this week, doctors have identified the second case ever of semi-identical twins.
Semi-identical twins, also known as sesquizygous twins, are a rare form of twins that share anywhere from 50 to 100% of their genomes. This is different from identical twins, who share 100% of their DNA, and fraternal twins, who share only 50%.
The case of semi-identical twins was discovered in Australia when the parents of two twin boys sought medical help for their sons’ fertility issues. After conducting genetic tests, doctors discovered that the twins were semi-identical.
The boys were conceived from two separate eggs that were fertilized by the same sperm. This is what makes them semi-identical. They share some of the same genetic material, but not all of it.
The first case of semi-identical twins was discovered in 2007 in the United States. Since then, there have been only two cases reported.
Semi-identical twins are incredibly rare, and it’s unclear why they occur. Scientists believe that it may be due to a rare event that occurs during the early stages of embryonic development.
The rarity of semi-identical twins means that there is still much to learn about them. Scientists are eager to study them in order to gain a better understanding of how they develop and how they differ from other types of twins.
The discovery of semi-identical twins is an exciting development in the field of genetics. It shows that there is still much to learn about the complexities of human development.